GB1047954A - Improvements in or relating to the production of urea - Google Patents
Improvements in or relating to the production of ureaInfo
- Publication number
- GB1047954A GB1047954A GB30740/63A GB3074063A GB1047954A GB 1047954 A GB1047954 A GB 1047954A GB 30740/63 A GB30740/63 A GB 30740/63A GB 3074063 A GB3074063 A GB 3074063A GB 1047954 A GB1047954 A GB 1047954A
- Authority
- GB
- United Kingdom
- Prior art keywords
- urea
- rectification
- solution
- water
- absorbing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C273/00—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups
- C07C273/02—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups of urea, its salts, complexes or addition compounds
- C07C273/04—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups of urea, its salts, complexes or addition compounds from carbon dioxide and ammonia
Abstract
Urea is produced by the reaction of CO2 with NH3, in stoichiometric amounts or using excess ammonia, to form an effluent containing urea, water, and unreacted CO2 and unreacted NH3 wherein unreacted CO2 and NH3 are separated from the effluent for re-use in producing urea, comprising subjecting the effluent to a first rectification at a gauge pressure of 10 Kg/cm.2 to 25 Kg/cm.2, at a head temperature of 90 DEG C. to 130 DEG C. and a still temperature of 130 DEG C. to 170 DEG C. to drive off NH3 and CO2 leaving a depleted liquid; subjecting the depleted liquid to a second rectification at a gauge pressure to 0 to 3 Kg/cm.2, a head temperature of 60 DEG C. to 110 DEG C. and a still temperature of 100 DEG to 140 DEG C. to drive off the remaining CO2 and NH3 leaving an aqueous solution containing urea, removing from the aqueous solution an amount of water equal to the water produced in the urea synthesis reaction to form a concentrated urea solution, separating urea from the concentrated urea solution by crystallization leaving a urea mother liquor, absorbing the CO2 and NH3 from the second rectification in the urea mother liquor to gauge pressure of 0 to 3 Kg/cm.2 to form an absorbate, absorbing the CO2 and NH3 from the first rectification in the absorbate at a pressure of 10 to 25 Kg/cm.2 to form a solution containing CO2 and NH3 for re-use in the production of urea. It is preferred to wash the gas recovered from the second absorbing step with a portion of the said liquor to remove CO2 therefrom and to liquefy the NH3 recovered from the second absorbing step and to use it in the production of urea. The heat of absorption evolved in the second absorbing step may be employed to evaporate water from the solution in the second rectification stage. Some of the water may be removed for preference from the urea solution at an absolute pressure of 40 to 100 mm. mercury, and the urea is for preference separated from the said aqueous solution by crystallization and centrifugation. The invention is described with reference to a flow sheet (not shown).
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3266662 | 1962-08-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1047954A true GB1047954A (en) | 1966-11-09 |
Family
ID=12365176
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB30740/63A Expired GB1047954A (en) | 1962-08-08 | 1963-08-02 | Improvements in or relating to the production of urea |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US3317601A (en) |
| DE (1) | DE1299295B (en) |
| GB (1) | GB1047954A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4365089A (en) * | 1980-09-05 | 1982-12-21 | Mitsui Toatsu Chemicals, Inc. | Synthesis of urea |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1668732A1 (en) * | 1966-10-25 | 1971-03-25 | Toyo Koatsu Ind Inc | Process for treating the unreacted ammonia and carbon dioxide contained in the synthesis of urea in the process of the synthesis autoclave |
| US3686305A (en) * | 1969-02-19 | 1972-08-22 | Mitsui Toatsu Chemicals | Method for synthesizing urea |
| US3668250A (en) * | 1969-08-19 | 1972-06-06 | Chemical Construction Corp | Urea synthesis process |
| JPS4919259B1 (en) * | 1969-08-30 | 1974-05-16 | ||
| US4036878A (en) * | 1972-06-12 | 1977-07-19 | Unie Van Kunstmestfabrieken, B.V. | Process for preparing urea |
| JPS5811432B2 (en) * | 1979-10-08 | 1983-03-02 | 三井東圧化学株式会社 | Urea synthesis method |
| US4256662A (en) * | 1980-01-18 | 1981-03-17 | Gorlovsky David M | Process for producing urea |
| EP3398935A1 (en) * | 2017-05-05 | 2018-11-07 | Casale Sa | Process and plant for the synthesis of urea |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1249757A (en) * | 1959-03-10 | 1960-12-30 | Chemical Construction Corp | Urea preparation process |
| GB948786A (en) * | 1959-10-23 | 1964-02-05 | Toyo Koatsu Ind Inc | An improvement in synthesis of urea |
| GB885692A (en) * | 1959-12-18 | 1961-12-28 | Toyo Koatsu Ind Inc | Improvements in or relating to the production of urea |
-
1963
- 1963-03-28 US US268769A patent/US3317601A/en not_active Expired - Lifetime
- 1963-04-30 DE DET23938A patent/DE1299295B/en active Pending
- 1963-08-02 GB GB30740/63A patent/GB1047954A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4365089A (en) * | 1980-09-05 | 1982-12-21 | Mitsui Toatsu Chemicals, Inc. | Synthesis of urea |
Also Published As
| Publication number | Publication date |
|---|---|
| DE1299295B (en) | 1969-07-17 |
| US3317601A (en) | 1967-05-02 |
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